Wobbler syndrome (cervical (neck) vertebral instability) is caused by
compression of the cervical spinal cord as a result of cervical vertebral
malformation-malarticulation or instability. Spinal cord compression injures
the portion of the spinal cord necessary for an animal to stand and move
normally.

In Doberman Pinscher and Great Dane dogs, the skeletal abnormality occurs
predominantly in the last three cervical vertebrae (the fifth, sixth and
seventh cervical vertebrae). The cause of the skeletal malformation or
malarticulation is unknown. Clinical studies suggest both genetics and
nutrition may play a role in the development of the defects. Research has shown
that, in some young dogs, excessive intake of a diet high in protein, energy,
calcium, and phosphorus accelerates growth. This may induce skeletal changes
such as those seen in some of these "wobbler" dogs.

The most common cervical vertebral abnormality is a narrowed spinal canal
through which the spinal cord must pass. The canal is reduced in height and
mildly compresses the spinal cord, especially during extension of the neck.
Other abnormalities in the cervical vertebrae include overgrowth of the body of
the vertebrae into the spinal canal, abnormal shape of the vertebral body or
the joints between the vertebrae, or excessive mobility of the cervical
vertebrae. These abnormalities eventually place so much stress on the
intervertebral discs that they degenerate, rupture, and then generate
additional pressure on the already compressed spinal cord. The result is an
acute problem secondary to chronic abnormalities in the last three cervical
vertebrae.

There is no evidence published to date that the disease can be predicted by
radiographic (x-ray) study of clinically normal dogs. Severe vertebral
malformation might indicate that a dog would be likely to experience spinal
cord compression. However, dogs with minimal radiographic changes may remain
free of clinical signs of spinal cord compression.

Wobbler syndrome is more commonly seen in younger Great Danes and older
Doberman Pinschers but may be seen in other breeds as well. Radiographs should
be taken in the normal position and with the neck extended and flexed. A
myelogram (contrast dye study of the spine) is necessary because the extent of
spinal cord compression cannot be determined with survey radiographs.

Symptoms

Initial signs of weakness and incoordination occur rapidly and are most
apparent in the hindlimbs. The clinical signs worsen slowly over succeeding
weeks. The hindlimbs often are spread wider apart than normal, causing the
hindquarters to sway from side to side. The hindlimbs may not fully extend,
causing a crouched posture with the toes scuffing on the ground with each step.
The degree of forelimb involvement varies from no observable abnormality to an
obvious stiffness and awkward use of the forelimbs. In mild cases, or early in
the disease, these signs may be most obvious as the dog turns corners, and may
be less apparent when the dog walks or runs along a straight path. An abrupt
change in speed or direction may exacerbate the neurological signs.

Because the nervous system involvement is limited to a small section of the
cervical spinal cord, these dogs remain alert and responsive. Dogs usually do
not exhibit pain on manipulation of the neck.

The reason some dogs do not show clinical signs until they are older is
likely due to mild initial vertebral abnormalities. With time, however,
continued movement of abnormal vertebral articulations causes secondary changes
in the intervertebral discs which result in disc degeneration and rupture. When
observing dogs move as part of the neurological examination, it must be
determined if any gait abnormality is because the dog cannot function normally
or because the dog does not want to function normally. The latter occurs from
pain associated with skeletal disease in the limbs, including hip dysplasia,
osteochondrosis dissecans of the cervical vertebrae in young, giant breed dogs,
and hypertrophic osteodystrophy. In dogs with these skeletal diseases, the
stride is usually shorter than normal, often creating a choppy gait. However,
these patients always know the position of their limbs, which are kept directly
under the body. Joint pain may be determined by palpation.

Diagnosis

Diagnosis of wobbler syndrome requires a more extensive evaluation than
plain survey radiographs (x-rays) can provide. A myelogram is used to confirm
not only the location of a compression but also the amount of spinal cord
swelling. Myelograms are common and safe diagnostic procedures when performed
with care and under the proper conditions. Laboratory tests on blood and
cerebrospinal fluid usually are within normal limits.

Treatment

With the first clinical episode, treatment is directed primarily at the
spinal cord injury and consists of corticosteroid administration to reduce
edema (swelling) that may be present in the compressed segment of the spinal
cord. However, medical therapy usually provides only temporary improvement at
best. Surgery provides spinal cord decompression and an opportunity to directly
repair some of the vertebral abnormalities. Although many techniques are
described, the most common surgical procedure is to remove any ruptured disc
material and then stabilize the vertebrae.

Prognosis

Prognosis depends on the severity of clinical signs and the degree of
skeletal disease present. If the dog was paralyzed and unable to stand before
surgery, the prognosis for recovery after surgery will be guarded. The dog that
was able to ambulate freely (but with incoordination) before surgery will have
a better prognosis. Although it is anticipated that surgery will stop
progression of clinical signs and result in improved function, it is the degree
of permanent spinal cord damage that determines the final outcome.

HandicappedPets.com has just documented the most heartwarming
story of Billy Bob, a Blue Doberman with Wobblers. This 5 minute video
shows that Handicapped Pets can live happy, healthy lives.